Drinking Water Contaminant Candidate List

CCL Highlights Draft CCL 2 CCL Quick Find The CCL as it relates to: The National Contaminant Occurrence Database The Unregulated Contaminant Monitoring Regulation The Review of Existing Regulations and Monitoring Requirements Meetings of the Drinking Water Contaminant Candidate List Classification Process Work Group of The National Drinking Water Advisory Council   You will need Adobe Acrobat Reader to view the Adobe PDF files on this page. See EPA's PDF page for more information about getting and using the free Acrobat Reader

Notice of a Public Meeting To Discuss Regulatory Determinations for the Second Contaminant Candidate List (CCL 2) and Updates for Unregulated Contaminant Monitoring and the CCL 3 - September 15, 2004

What is the Drinking Water Contaminant Candidate List?

The drinking water Contaminant Candidate List (CCL) is the primary source of priority contaminants for evaluation by EPA’s drinking water program. The Safe Drinking Water Act (SDWA), as amended in 1996, requires EPA to publish a list of contaminants every five years which, at the time of publication, are not subject to any proposed or promulgated national primary drinking water regulations. Contaminants on the CCL are known or anticipated to occur in public water systems and may require regulations under SDWA.

EPA conducts research on health, analytical methods, treatment technologies, effectiveness, costs, and occurrence for drinking water contaminants on the CCL. The Agency also develops drinking water guidance and health advisories, and makes regulatory determinations for priority contaminants on the CCL.

When was the first CCL published?

The first CCL was published in March of 1998 and included 50 chemicals or chemical groups and 10 microbial contaminants.

• 1998 Final Drinking Water Contaminant Candidate List

How Does the CCL relate to the occurrence database and unregulated contaminant monitoring?

EPA has established a National Drinking Water Contaminant Occurrence Database (NCOD) and an Unregulated Contaminant Monitoring Regulation (UCMR) as required by SDWA.

The NCOD stores data on the occurrence of both regulated and unregulated contaminants. It provides the basis for identifying contaminants that may be placed on future CCLs and support EPA Administrator's decisions to regulate contaminants in the future. The NCOD is also expected to support the review of existing regulations and monitoring requirements every six years.

EPA developed regulations for monitoring certain unregulated contaminants in 1999. These contaminants are listed in the UCMR. The CCL Occurrence Priority list is the primary source of contaminants for the unregulated monitoring list, which must not exceed 30 contaminants.

• The CCL as it relates to: The National Contaminant Occurrence Database
• The CCL as it related to: The Unregulated Contaminant Monitoring Regulation

For what contaminants did EPA make regulatory determinations?

On July 18, 2003, EPA announced its final determinations for a subset of contaminants on the 1998 CCL (68 FR 42898), which concluded that sufficient data and information were available to make the determination that a regulation was not appropriate for the following nine contaminants: Acanthamoeba, aldrin, dieldrin, hexachlorobutadiene, manganese, metribuzin, naphthalene, sodium, and sulfate.

• Regulatory Determinations for Priority Contaminants on the Drinking Water Contaminant Candidate List

What contaminants are included in the Draft CCL 2?

On April 2, 2004 EPA announced its preliminary decision to carry over the remaining 51 contaminants (nine microbiological and 42 chemical contaminants or contaminant groups). For the list see the tables in both the 1998 CCL and the Draft CCL 2. This will allow the Agency to continue with research and data collection activities related to the list, prepare to make regulatory determinations in the 2006 time-frame using the data collected from these activities, and to focus resources on completing ongoing work with the National Drinking Water Advisory Council (NDWAC) on an expanded process for classifying drinking water contaminants in the future.

Comments may be submitted by following the instructions provided in the notice and must be received or postmarked by midnight June 1, 2004.

For questions about the Draft CCL 2 or the Federal Register Notice, contact EPA's Safe Drinking Water Hotline at (800) 426-4791 or e-mail: sdwhotline@bah.com.

• Draft CCL 2 Federal Register Notice (comment period ended June 1, 2004)

What approach did EPA use to develop the Draft CCL 2?

The Agency’s approach to the Draft CCL 2 is to continue using the remaining contaminants on the 1998 CCL for prioritizing research and making regulatory determinations while working with the NDWAC (The NDWAC provides independent advice, consultations, and recommendations to EPA on matters related to the activities, function, and policies of the Agency under the SDWA) and stakeholders to complete a review of the National Research Council (NRC) recommendations for developing a more comprehensive and transparent CCL listing process.

The NRC identified a number of opportunities to strengthen and expand the analytical process upon which the 1998 CCL was based. The NRC recommendations focused on developing a larger initial list and on identifying new approaches for screening larger numbers of potential CCL contaminants. While the NRC recommendations would expand the universe of contaminants and suggest a change in the manner in which contaminants are selected for the CCL, they are based on the same fundamental principles used in developing the 1998 CCL -- a focus on health impacts and contaminant occurrence.

• National Drinking Water Advisory Council

Does the Draft CCL 2 impose any requirements?

No, neither this Draft CCL 2 nor the Final CCL 2, when published, imposes any requirements on anyone. Contaminants on the list may become the subject of future regulations. The public would be provided additional opportunities to comment as part of the rule making process.

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